Genmab, with its U.S. headquarters in Plainsboro, announced that it will acquire all shares of Merus. The transaction is expected to close by early in the first quarter of 2026.
The addition of petosemtamab, Merus’ lead asset, to Genmab’s promising late-stage pipeline is a compelling strategic fit with Genmab’s portfolio and aligns with its expertise in antibody therapy development and commercialization in oncology.
Following the closing of the transaction, Genmab will have four proprietary programs expected to drive multiple new drug launches by 2027.
“The proposed acquisition of Merus clearly aligns with our long-term strategy. It has the potential to significantly accelerate our evolution into a global biotechnology leader by providing durable growth for the company well into the next decade,” said Jan van de Winkel, Ph.D., president and chief executive officer of Genmab.
“Petosemtamab has the potential to be a transformational therapy for patients living with head and neck cancer. With our proven track record of success, both in clinical development and in commercialization, we are confident that we will be able to unlock the promise of petosemtamab.”
Petosemtamab has been granted two Breakthrough Therapy Designations (BTD) by the U.S. Food and Drug Administration (FDA) for first- and second-line plus head and neck cancer indications.
Compelling Phase 2 data were presented at the American Society for Clinical Oncology (ASCO) 2025 Annual Meeting, showing both an overall response rate and median progression-free survival that were substantially higher than standard of care.
Merus is currently running two Phase 3 trials in first- and second/third-line head and neck cancer, with topline interim readout of one or both trials anticipated in 2026. Based on Genmab’s experience in late-stage development and excellence in commercial execution, Genmab anticipates the potential for the initial launch of petosemtamab in 2027, subject to clinical results and regulatory approvals.
Genmab also intends to broaden and accelerate petosemtamab’s development with potential expansion into earlier lines of therapy. Following its initial anticipated approval, Genmab believes that petosemtamab will be accretive to EBITDA with at least $1 billion annual sales potential by 2029, with multibillion-dollar annual revenue potential thereafter.
PJT Partners and Morgan Stanley & Co. International plc are acting as joint financial advisors to Genmab, and A&O Shearman and Kromann Reumert as its legal advisors.
Jefferies LLC is acting as financial advisor to Merus, and Latham & Watkins and NautaDutilh as its legal advisors.
